Tensioning and regulating device for the passage of weft threads of different thickness



Sept. 12, 1967 R. B. GOLOBART 3,340,903

TENSIONING AND REGULATING DEVICE FOR THE PASSAGE OF WEFT THREADS OF DIFFERENT THICKNESS Filed Sept. 24, 1965 1 3 Sheets-Sheet 1 INVEN TOR.

RAMON EAL/16084 60108407 sept. 12 1967 R. B. GOLOBART 3 340,903

TENSIONING AND REGULA'IING DEVICE FOR THE PASSAGE OF WEF'T THREADS OF DIFFERENT THICKNESS Filed Sept. 24, 1965 5 Sheets-Sheet 2 F/G.3 /5 v v 4 3 4 INVENTOR.

RAMO/Y 134M605? comm? Sept. 12, 1967 TENSIONING AND Filed Sept. 24, 1965 B. GOLOBART ULATING DEVICE FOR THE SSAGE OF WEFT THREADS OF DIFFERENT THICKN 5 Sheets-Sheet 3 FIGS 22 INVENTOR.

RAMON 94446054 GOLOBART Patented Sept. 12, 1967 4 Claims. (51. 139-194 The present invention relates to a tensioning and regulating device for the passage of weft threads of different thickness.

Different braking or tensioning systems for the insertion of weft threads, based on the passage through more or less adjustable obstacles or on springs for the compensation of tension, are used in looms, especially in the case of shuttleless looms. These systems work satisfactorily as long as the nature of the fabric does not require different or rather thin wefts. No satisfying result is obtained, however, if the Weft threads are of different thickness and the passage through the shed has to be effected at great speed. On the other hand, the variable speed of the Weft inserting devices in shuttleless looms causes abrupt passages accompanied by the danger of breaking the weft, thus affecting the aspect of the woven fabric, especially in the case of looms with double Weft inserting member or even more if different qualities of Weft threads or those of variable thickness are to be inserted.

The hitherto known tensioning devices for weft threads are of static nature, i.e. they do not adjust themselves adequately to inconstant moments of the insertion of the weft thread; in general, the very weft thread or threads themselves put into operation the tensioning elements when passing, thus achieving the braking or tensioning which causes the thinning of the weft thread and in many cases even the breaking of the same.

It is the object of the present invention to overcome the said difficulties by rendering possible the automatic tensioning of the weft threads at the critical moments and in timed relationship with the variable travel speed of the weft inserting member, so that at a given moment the braking action on the weft thread may be equal to zero, if this is necessary for the texture of the fabric to be woven.

The device according to the invention is secured to a fixed point on the loom by means of a gudgeon at the side where the weft thread is inserted, means being provided for the graduation of the independent regulation of tension for each thickness of the weft thread and for an easy regulation of the storage of tensioning power, as well as interchangeable and independent thread-guides which can be adapted to the thickness of each Weft thread.

The tension can be adjusted in timed relationship with the speeds of the weft inserting member by means of a lever, which is put into motion by a rod co-operating with a cam, which, in turn, receives its movement from a rotating shaft of the loom. The outline of this cam is adapted to the sinuosities which are conditioned by the regulation of the tension of the weft threads. This device may serve not only for one weft thread, but for a number of threads of different qualities and thickness.

The device consists of two parallel supports mounted on a base forming the whole to which the different elements are secured. These, when put into operation, cause the automatic regulation of tension for each weft thread. The base is provided with even rectified plates of rather hard material which may be replaced when worn as a consequence of the passage of the weft thread. The upper part of the two supports carries two fixed shafts, on one of them being freely accommodated a number of blocks, against which rest a number of thin flexible steel sheets bent at an approximately right angle, their two ends being united by an arched portion which fulfills the function of a spring in order to exert the adequate tension on the weft threads by contact with the said rectified even plates of the base at the critical moments in accordance with the movements and pressure of an oscillatory lead, to which a series of screws-one for each block-are secured, so as to serve individually for the graduation of the independent opening of the flexible sheets which may correspond to the thickness of each weft thread.

One end of the oscillatory lead rests on a lever provided with an adjusting slot for controlling the oscillation of the lead, the said lever being connected with one end of a rod, the other end of which carries a roller which slides on the cam of the appropriate outline for transmitting to the lead the cycle of oscillatory movements required for the regulation of the flexible sheets according to the tensioning requirements and thickness of the weft threads.

Each block is provided with a stud bolt carrying one projecting prolonged end of a helical spring, the coils of these springs being mounted on the other fixed shaft of the supports and each of the other ends of the springs being secured to the lateral face of a free ring of polygonal outline, which by means of as many turns as desired graduates the required tension of the helical spring for each flexible sheet. One of the polygonal faces of the said ring rests on a safety plate which serves for its fastening, thus rendering impossible any accidental modification of the graduation of the whole.

At the lower parts of the supports there are secured two platesone opposite the otherparallel to the fixed shafts and provided with circular openings, divided into two in longitudinal and diametral direction, which accommodate a corresponding number of replaceable threadguiding rings, the passage of the latter corresponding to the thickness of each weft thread which has to pass through it. The weft threads enter through the respective guide rings at the driving side of the flexible sheets, pass then at the interior of the device between the even rectified plate of the base and the graduated flexible sheet and come out through the guide rings of the opposite plate, adequately tensioned.

In order that the invention may be clearly understood, an embodiment thereof will now be described by way of example with reference to the accompanying drawings, wherein FIG. 1 represents a sectional view of the device;

FIG. 2 is a side elevational view from the opposite side of FIG. 1;

FIG. 3 is a plan view of the device with four tensioning elements with some parts in section;

FIG. 4 is a front elevation'al view of the device with four tensioning elements showing the replaceable threadguiding rings;

FIG. 5 is a sectional view similar to that of FIG. 1 showing the tensioning elements of the weft-thread in braking position;

FIG. 6 is a sectional view similar to that of FIG. 1 showing the tensioning elements of the weft-thread in nearly inoperative position; and

FIG. 7 is a sectional view similar to that of FIG. 1 showing the tensioning elements of the weft-thread in completely inoperative position.

As shown in FIGS. 1, 2, 3 and 4, the device comprises a support -1 provided with a divided gudgeon 2, 3, through which it may be secured to a fixed point of the loom (not shown) by means of screws 4 (FIG. 3). The support 1 is connected with an opposite support 8 through a base 5 and two fixed shafts 6 and 7.

The fixed shaft 6 carries a number of oscillatory blocks 9, each of which is provided with a flexible steel sheet 10, bent at an approximately right angle, their two ends being united by an arched portion 11, which fulfills the function of a spring. The sheets 10 are secured to the respective block 9 by means of screws 12.

One end of the fixed shaft 6 carries a lever 13 provided with an adjusting slot 14 for a connecting rod 15 which is adapted to impart an oscillatory movement to the lever 13 derived from a cam (not shown). This lever 13 is connected with a lead 16 which is arranged parallelly to the fixed shaft 6 and connected to a bracket 17 on the other extreme end of the fixed shaft 6.

A number of screws 18 with the corresponding lock nuts 1% are mounted on the lead 16 for the graduation and fastening of the flexible sheets 10 to an adequate, previously determined position and tension.

A stud bolt 20 is screwed to the inner face of each block 9. These stud bolts simultaneously support and serve as guides for the projecting prolonged end 21 of a corresponding number of helical springs 22 arranged on the fixed shaft 7, the other end 23 (FIG. 3) of these springs 22 being secured to the lateral face 24 (FIG. 3)/ of a ring 25 of polygonal outline which by means of as many turns as desired, graduates the tension which is re quired by each flexible sheet 10. In order to prevent any loosening of the ring 25, the end 27 (FIG. 1) of a safety plate 26 is secured by means of screws 28 to a lead 29, the extreme ends of which are secured to the supports 1 and 8 by means of screws 28.

A number of even, rectified, replaceable plates 30 of rather hard material are secured to the base 5 by means of screws 31 at a ratio of one per flexible sheet 10.

The lower parts of the supports 1 and 8 are provided with two plates 32 and 33, one opposite the other and in parallel position to the two fixed shafts 6 and 7. These plates have circular openings, divided into two in longitudinal and diametral direction, accommodating a corresponding number of replaceable thread-guiding rings 34 and 35.

FIGURE 5 shows the passage of a weft thread 36 through the entry thread-guiding ring 34 and the exit thread-guiding ring 35 and under pressure between the flexible sheet 10 and the even plate 30..The opening for the passage of the weft thread 36 between the flexible sheet 10 and the plate 3%) may be adjusted by the screw 18 according to the thickness of the thread and the tension to be exerted by the tension-storing spring 22 through the polygonal ring 25, finally fixed by sheet 26. The raised position of the lever 13 in accordance with the cycle of movements transmitted by the cam (not shown) also cooperates in the retention of the weft thread 36.

FIGURE 6 shows the passage of the weft thread 36 through the entry thread-guiding ring 34 and the exit thread-guiding ring 35 under the pressure of the flexible sheet 10 only and freed from the even plate 30. The screw 18 is adjusted as before, the lever 13, however, has come down according to the convenient cycle of movement; thus, by means of the screw 18, the flexible sheet is raised maintaining, however, and even increasing the tension exerted by the tension-storing spring 22, so that the tension of the weft thread 36 is inferior to that represented by FIGURE 5.

FIGURE 7 shows the passage of the weft thread 36 through the entry thread-guiding ring 34 and the exit thread-guiding ring 35 completely free from the flexible sheet 10 and the even plate 30, due to the fact that the lever 13 has come down as far as possible, thus urging the flexible sheet 10 to rise by means of screw 1'8; the weft thread now remains completely free and untensioned as required at this critical moment of the weaving process.

The above-mentioned three tensioning positions may be combined as desired in one and the same insertion of weft thread; moreover, different intermediate positions in accordance with the desired graduation are possible as well.

What I claim is:

1. Tensioning and regulating device for the passage of weft threads of different thickness, adapted to be mounted on a shuttleless loom having at least one weft inserting member, comprising two parallel supports mounted on a base provided with a number of even, rectified, replaceable plates of hard material at a ratio of one per passage of weft thread; two parallel fixed shafts carried by the upper part of the said supports; a number of blocks freely accommodated on one of the said shafts and against which rest a corresponding number of thin flexible sheets bent at an approximately right angle, the bent portions of which fulfill the function of a spring in order to exert the adequate tension on the weft threads by contact with the said rectified even plates of the base in co-operation with a corresponding number of adjustable helical spring an oscillatory lead arranged in front of the said blocks and provided with a series of adjustable screws at a ratio of one per block, adapted to individually adjust the position of the said flexible sheets with respect to said even plates in accordance with the thickness and quality of each weft thread passing therebetween; and a lever connected to one extreme end of the said oscillatory lead and adapted to impart to this lead an oscillatory movement in timed relationship to the speed of the weft inserting member of the loom.

2. Tensioning and regulating device as claimed in claim 1, wherein the said lever is provided with an adjusting slot through which it is adjustably connected to one end of a rod adapted to impart to the said lever and the oscillatory lead connected therewith the cycle of oscillatory movements required for the regulation of the said flexible sheets according to the tensioning requirements and thickness of the weft threads.

3. Tensioning and regulating device as claimed in claim 1, wherein the inner face of each of the said blocks is provided with a stud bolt carrying one projecting prolonged end of said helical springs, the coils of said springs being mounted on the other fixed shafts carried by the said supports, and each of the other end of said helical springs being secured to the lateral face of a free ring of polygonal outline which by means of as many turns as desired graduates the required tension of said helical springs for each flexible sheet, one of the polygonal faces of the said ring resting on a safety plate which serves for its fastening, thus rendering impossible any accidental modification of the graduation of the whole.

4. Tensioning and regulating device as claimed in claim 1, comprising two plates secured at the lower part of the said supports, said plates being arranged one opposite the other, parallel to the said fixed shafts carried by the supports and provided with circular openings divided into two in longitudinal and diametral direction, a replaceable thread-guiding ring in each of said openings of adequate size for each thickness of weft thread, said weft threads entering through said thread-guiding rings on the driving side of the flexible sheets, passing through the interior of the device between the even rectified plates of the base and the graduated flexible sheets, and leaving,

6 adequately tensioned, through said thread-guiding rings 3,129,902 4/1964 Iuillard 139-122 X of the opposite plate. 3,276,482 10/ 1966- Liebchen 139-122 References Cited 894 755 3/ 1 ZZ F PATENTS rance. UNITED STATES PATENTS 5 1,383,420 11/1964 France- 2,158,828 5/1939 Merkel 242-149 2,749,946 6/1956 Pfarrwaller 139-126 MERVIN STEIN, Primary Examiner.

2,819,736 4/1958 Pfarrwaller 139- 194 2,981,497 4/1961 Schurich 242- 149 KEE Emmmer- 

1. TENSIONING AND REGULATING DEVICE FOR THE PASSAGE OF WEFT THREADS OF DIFFERENT THICKNESS, ADAPTED TO BE MOUNTED ON A SHUTTLELESS LOOM HAVING AT LEAST ONE WEFT INSERTING MEMBER, COMPRISING TWO PARALLEL SUPPORTS MOUNTED ON A BASE PROVIDED WITH A NUMBER OF EVEN, RECTIFIED, REPLACEABLE PLATES OF HARD MATERIAL AT A RATIO OF ONE PER PASSAGE OF WEFT THREAD; TWO PARALLEL FIXED SHAFTS CARRIED BY THE UPPER PART OF THE SAID SUPPORTS; A NUMBER OF BLOCKS FREELY ACCOMMODATED ON ONE OF THE SAID SHAFTS AND AGAINST WHICH REST A CORRESPONDING NUMBER OF THIN FLEXIBLE SHEETS BENT AT AN APPROXIMATELY RIGHT ANGLE, THE BENT PORTIONS OF WHICH FULFILL THE FUNCTION OF A SPRING IN ORDER TO EXERT THE ADEQUATE TENSION ON THE WEFT THREADS BY CONTACT WITH THE SAID RECTIFIED EVEN PLATES OF THE BASE IN CO-OPERATION WITH A CORRESPONDING NUMBER OF ADJUSTABLE HELICAL SPRINGS; AN OSCILLATORY LEAD ARRANGED IN FRONT OF THE SAID BLOCKS AND PROVIDED WITH A SERIES OF ADJUSTABLE SCREWS AT A RATIO OF ONE PER BLOCK,ADAPTED TO INDIVIDUALLY ADJUST THE POSITION OF THE SAID FLEXIBLE SHEETS WITH RESPECT TO SAID EVEN PLATES IN ACCORDANCE WITH THE THICKNESS AND QUALITY OF EACH WEFT THREAD PASSING THEREBETWEEN; AND A LEVER CONNECTED TO ONE EXTREME END OF THE SAID OSCILLATORY LEAD AND ADAPTED TO IMPART TO THIS LEAD AN OSCILLATORY MOVEMENT IN TIMED RELATIONSHIP TO THE SPEED OF THE WEFT INSERTING MEMBER OF THE LOOM. 